1. Technical Field
The present invention relates to an image reading device, an image reading method, and an image reading program.
2. Related Art
A copier (including a composite machine or the like having a copy function) for optically reading a manuscript on which an image is recorded by a scanner, creating image data in accordance with a result of the reading, and converting the created image data into print data for printing has been generally known.
Further, a print image processing system has been known (see JP-A-2005-244802 (hereinafter referred to as Patent Document 1). In the print image processing system, when an image printed on a print paper in which one IC tag is embedded in each area that is divided in a net-like manner is scanned for copying, copying is prohibited for each area in which the IC tag in which output prohibit information is stored is embedded.
In the copier, there is a problem as described below.
When a selected manuscript is set on the scanner, a user generally inputs the size of the manuscript to the scanner so that the scanner recognizes an area for scanning. However, such an input operation is extremely troublesome for the user. Further, a scanner capable of omitting such an input operation has been also known. In the scanner, pre scanning is performed before main scanning to recognize the range in which the manuscript is placed, and only the recognized range is scanned when main scanning is performed. However, a time required for the copy operation is increased due to the pre scanning.
Further, when a manuscript is copied, there is a case that it is inadequate to copy all of the content recorded on the manuscript. For example, there is a case that a content whose copy is restricted due to copyright law, information that is kept secret from outsiders, personal information, or the like is included in a part area of the manuscript. In the past, copying of such a part area of the manuscript is prevented by painting the part that is inadequate to be copied or by covering the part with another paper by the user, so that it is very laborious for the user. Further, as in Patent Document 1, even when the user operates an output prohibit information writing device with respect to a paper to write output prohibit information in each of IC tags, the operation is very laborious for the user. Further, in the reading device of Patent Document 1, it is necessary to read information from the IC tag embedded in each of the areas of the paper divided in a net-like manner in order to recognize a copy prohibited area on the paper. Accordingly, a lot of time is required for the copy operation.
Further, there is also a problem from the viewpoint of saving a memory (storage device) equipped in the copier. Generally, image data loaded by scanning a manuscript is once accumulated in a memory in the copier before converted into print data. When stored in the memory, in order to reduce consumption of memory, the image data is stored after compressed by a predetermined compress method. Herein, when the type of the image such as a character, a photograph, a computer graphic, or the like is different, the best suited compress method becomes different from the view point of image quality or compression rate. Accordingly, when a plurality of images of different type exist on one manuscript, if the compress method can be changed for every area of image whose type is different, each of the images of different type can be respectively stored to have a sufficient image quality, and memory consumption can be reduced as a whole. However, it is burden for the copier to discriminate a character area or a photograph area on a manuscript by performing an analyzing processing to the image data obtained by the scanning, and it requires a lot of processing time. Further, when the discrimination is failed in the analyzing processing, an appropriate compression of image data is not provided in the end.